Background: Segmentectomy provides an anatomic, parenchymal-sparing strategy for patients with limited lung function. Recently, interest has been renewed in segmentectomy for the treatment of early stage lung cancer. Methods: We reviewed the medical records of all patients undergoing segmentectomy from January 1999 through December 2004. Survival curves were estimated using the Kaplan-Meier method. Results: There were 113 consecutive patients (58 men, 55 women); median age was 72.5 years (range, 30 to 94 years). Median forced expiratory volume in 1 second was 1.53 L (range, 0.5 L to 3.27 L). Median diffusion capacity of lung for carbon monoxide was 69% predicted (range, 23% to 129%). Significant comorbidities were present in 62 patients (55%). There was no perioperative mortality. Major morbidity occurred in 28 patients (25%). Mean tumor size was 2.1 cm. Resection margins were negative in all cases. Ninety-two patients (81%) were stage I. Overall 5-year survival was 79% for stage IA patients. Current smoking, diffusion capacity of lung for carbon monoxide less than 69%, tumor size greater than 2 cm, N2 disease, and advanced histology grade were associated with decreased survival by univariate analysis. In a multivariate model, only tumor size greater than 2 cm remained significant. Tumor recurrence was observed in 39 patients (35%): local in 17 patients (15%) and distant only in 22 (20%). For stage IA patients with T1a lesions, local recurrence was 5% and distant recurrence was 13%. Five-year recurrence-free survival of these patients was 69%. Conclusions: Pulmonary segmentectomy can be performed safely in selected patients with preoperative reduced lung function and comorbidities. For stage IA disease, survival approximates that seen after lobectomy, with similar local recurrence rates for patients with T1a tumors. © 2012 The Society of Thoracic Surgeons.